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United States Patent |
6,216,672
|
Mishima
,   et al.
|
April 17, 2001
|
Fuel supply system of outboard motor
Abstract
An outboard motor of fuel injection type includes a fuel supply system
which comprises a fuel tank in which a fuel is stored, a low pressure fuel
filter and a low pressure fuel pump connected to the fuel tank through a
fuel supply hose, a vapor separator connected to the low pressure fuel
pump through a low pressure fuel hose, a high pressure fuel pump disposed
inside the vapor separator, a pressure regulator disposed inside the vapor
separator, a fuel hose having one end connected to the high pressure fuel
pump, a branch pipe incorporated on the way of the fuel hose and having
one end connected to the pressure regulator, and a delivery pipe connected
to another one end of the branch pipe. A fuel injector is connected to the
delivery pipe and adapted to inject the fuel with pressure regulated by
the pressure regulator.
Inventors:
|
Mishima; Shuichi (Iwata, JP);
Ito; Jun (Hamamatsu, JP)
|
Assignee:
|
Suzuki Kabushiki Kaisha (Hamamatsu, JP)
|
Appl. No.:
|
340037 |
Filed:
|
June 28, 1999 |
Foreign Application Priority Data
| Jun 29, 1998[JP] | 10-182619 |
Current U.S. Class: |
123/516; 123/509 |
Intern'l Class: |
F02M 041/00 |
Field of Search: |
123/516,518,519,509,510,497
|
References Cited
U.S. Patent Documents
5103793 | Apr., 1992 | Riese et al. | 123/516.
|
5389245 | Feb., 1995 | Jaeger et al. | 123/516.
|
5647331 | Jul., 1997 | Swanson | 123/516.
|
5819711 | Oct., 1998 | Motose | 123/516.
|
5855197 | Jan., 1999 | Kato | 123/516.
|
5865160 | Feb., 1999 | Kato | 123/516.
|
5873347 | Feb., 1999 | Kato et al. | 123/497.
|
5915363 | Jun., 1999 | Iwata et al. | 123/516.
|
Primary Examiner: Miller; Carl S.
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Claims
What is claimed is:
1. A fuel supply system of an outboard motor having an engine holder, an
engine disposed above the engine holder in a state installed to a hull and
including a cylinder block, and an intake device disposed on a side of the
engine with a space therefrom and including an intake manifold, said fuel
supply system comprising:
a fuel tank in which a fuel to be supplied is stored;
a low pressure fuel filter and a low pressure fuel pump connected to the
fuel tank through a fuel supply hose;
a vapor separator connected to the low pressure fuel pump through a low
pressure fuel hose and disposed in the space between the cylinder block
and the intake device;
a high pressure fuel pump disposed inside the vapor separator;
a pressure regulator disposed inside the vapor separator;
a fuel hose having one end connected to the high pressure fuel pump;
a branch pipe interposed a the fuel hose and having a first end connected
to the pressure regulator through a hose; and
a delivery pipe connected to a second end of the branch pipe.
2. A fuel supply system according to claim 1, further comprising a fuel
injector connected to the delivery pipe and adapted to inject the fuel
with pressure regulated by the pressure regulator.
3. A fuel supply system according to claim 1, wherein said vapor separator
is integrally mounted to a mount base of the outboard motor.
4. A fuel supply system according to claim 3, wherein said mount base is
the intake manifold.
5. A fuel supply system according to claim 1, further comprising a high
pressure fuel filter interposed along the fuel hose operatively connecting
the high pressure fuel pump and the delivery pipe.
6. A fuel supply system according to claim 1, wherein said vapor separator
has an inner space sectioned by a partition plate into upper and lower
portions in which the high pressure fuel pump and the pressure regulator
are arranged respectively, said upper and lower portions being
communicated through a port formed to the partition plate.
7. A fuel supply system of an outboard motor having an engine holder, an
engine and an intake device, the engine including a cylinder block and
disposed above the engine holder in the outboard motor installed on a
hull, the intake device including an intake manifold and disposed on a
side of the engine, said fuel supply system comprising:
a fuel tank;
a low pressure fuel filter and a low pressure fuel pump connected to the
fuel tank through a fuel supply hose;
a vapor separator connected to the low pressure fuel pump through a low
pressure fuel hose and disposed in a space between the cylinder block and
the intake device;
a high pressure fuel pump disposed inside the vapor separator;
a pressure regulator disposed inside the vapor separator;
a fuel hose having one end connected to the high pressure fuel pump;
a branch pipe interposed along the fuel hose and having a first end
connected to the pressure regulator through a hose; and
a delivery pipe connected to a second end of the branch pipe.
8. A fuel supply system according to claim 7, further comprising a fuel
injector connected to the delivery pipe and configured to inject the fuel
with pressure regulated by the pressure regulator.
9. A fuel supply system according to claim 7, wherein said vapor separator
is integrally mounted to a mount base of the outboard motor.
10. A fuel supply system according to claim 7, wherein said vapor separator
is integrally mounted to the intake manifold.
11. A fuel supply system according to claim 7, further comprising a high
pressure fuel filter interposed along the fuel hose connecting the high
pressure fuel pump and the delivery pipe.
12. A fuel supply system according to claim 7, wherein:
said vapor separator comprises a partition plate and a communication port
in the partition plate;
said partition plate divides an inner space of said vapor separator into an
upper portion and a lower portion which are communicated through the
communication port; and
the high pressure fuel pump is disposed in the upper portion and the
pressure regulator is disposed in the lower portion.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a fuel supply system of an outboard motor.
In a known art, an outboard motor is provided with a fuel supply system or
apparatus for fuel injection type engine, and such fuel supply system is
operated in a manner that a fuel in a fuel tank is guided to a vapor
separator by means of a low pressure fuel pump, then delivered to a high
pressure fuel filter by means of a high pressure fuel pump and filtered
therein, and thereafter, is guided to an intake port by a fuel injector
through a delivery pipe. An extra amount of the fuel fed to the fuel
injector is delivered to a pressure regulator from a downstream side of
the delivery pipe and is thereafter returned to the vapor separator after
a fuel pressure has been lowered.
In the conventional structure, however, since the vapor separator and the
pressure regulator are arranged apart from each other around an engine.
Accordingly, a space around the engine is not effectively utilized and, in
addition, duct or pipe arrangement is made complicated.
Furthermore, in the conventional structure, fuel elements or members
constituting the fuel supply system such as a vapor separator, a pressure
regulator, a fuel pump, a fuel filter, etc. are arranged or mounted to
various portions of the engine, thus being inconvenient for performing
maintenance or inspection of the engine and making it difficult to realize
a compact structure of the engine.
SUMMARY OF THE INVENTION
An object of the present invention is to substantially eliminate defects or
drawbacks encountered in the prior art mentioned above and to provide a
fuel supply system of an outboard motor having a compact structure and
having an improved arrangement of fuel elements to easily carry out
maintenance work.
This and other objects can be achieved according to the present invention
by providing a fuel supply system of an outboard motor, particularly of a
fuel-injection type, comprising:
a fuel tank in which a fuel to be supplied is stored;
a low pressure fuel filter and a low pressure fuel pump connected to the
fuel tank through a fuel supply hose;
a vapor separator connected to the low pressure fuel pump through a low
pressure fuel hose;
a high pressure fuel pump disposed inside the vapor separator;
a pressure regulator disposed inside the vapor separator;
a fuel hose having one end connected to the high pressure fuel pump;
a branch pipe incorporated on the way of the fuel hose means and having one
end connected to the pressure regulator through a hose; and
a delivery pipe connected to another one end of the branch pipe.
In a preferred embodiment, a plurality of fuel injectors are connected to
the delivery pipe and adapted to inject the fuel with pressure regulated
by the pressure regulator.
The respective elements or parts mentioned above are integrally mounted to
a mount base such as intake manifolds of an outboard motor.
A high pressure fuel filter is further disposed on the way of the fuel hose
operatively connecting the high pressure fuel pump and the delivery pipe.
The vapor separator has an inner space sectioned by a partition plate into
upper and lower portions in which the high pressure fuel filter and the
pressure regulator are arranged respectively.
According to the structure of the fuel supply system of an outboard motor
mentioned above, the fuel supply system can be made more unitive and the
number of parts or elements to be arranged can be reduced, thus making the
entire structure simple and compact.
The fuel elements or parts constituting the fuel supply system are mounted
integrally to the intake manifold as mount base. Therefore, all the
elements or parts of the fuel supply system can be integrally dismounted
by removing the low pressure fuel hose from the low pressure fuel pump. As
a result, the maintenance of the engine can be effectively performed and
the fuel supply system itself can be made more unitive. Furthermore,
re-assembling of such fuel supply system can be also done more simply.
The location of the high pressure fuel filter between the vapor separator
and the delivery pipe can prevent foreign matters or the like from
entering into the fuel injectors, thus the system being reliable.
Still furthermore, according to the present invention, since the fuel
discharge port as the high pressure fuel outlet is formed to, for example,
the upper portion of the vapor separator and the pressure regulator as the
high pressure fuel inlet is located to, for example, the lower portion of
the vapor separator, the overlapped arrangement of the fuel hoses can be
prevented, thereby making the pipe (piping) arrangement compact.
The nature and further characteristic features of the present invention
will be made more clear from the following description made with reference
to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a left-side view of an outboard motor having a fuel supply system
according to one embodiment of the present invention in a state mounted to
a hull;
FIG. 2 is a side view, in an enlarged scale, of an engine of the outboard
motor of FIG. 1; and
FIG. 3 is a block diagram of the fuel supply system of the outboard motor
of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One preferred embodiment of the present invention will be described
hereunder with reference to the accompanying drawings.
First, FIG. 1, shows an outboard motor 1 equipped with a fuel supply system
or apparatus according to the present invention in a state mounted to a
transom 5a of a hull 5.
The outboard motor 1 is provided with an engine holder 2 above which an
engine or engine unit 3 is disposed. The engine holder 2 is provided with
a bracket 4 through which the outboard motor 1 is mounted to the transom
5a of the hull 5.
Next, FIG. 2, shows the engine 3 of the outboard motor, the engine unit 3
mounted to the outboard motor 1 is, for example, a water-cooled
four-stroke-cycle three-cylinder engine, and is assembled with a cylinder
head 6, a cylinder block 7, crank case 8, etc. The outer periphery of the
engine 3 is covered by an outboard motor cover 9.
The cylinder block 7 is arranged to a portion at a rear side of the crank
case 8 disposed at the most forward portion, left-side as viewed in FIG.
2, of the engine 3, and the cylinder head 6 is disposed at the rear
portion of the cylinder block 7. The rear side portion of the cylinder
head 6 is covered by a head cover 10, and a crank shaft 11 is arranged
substantially vertically at a mating portion of the crank case 8 and the
cylinder block 7 (FIG. 1).
Referring to FIG. 1, a drive shaft housing 12 is disposed below the engine
3. An upper end of a drive shaft 13 is coupled to the lower end of the
crank shaft 11 through a spline coupling, for example, and the drive shaft
13 extends downward therefrom inside the drive shaft housing 12. The lower
end of the drive shaft 13 is engaged with a bevel gear 15 and a propeller
shaft arranged in a gear case 14 disposed below the drive shaft housing 12
thereby to drive a propeller 17 of the outboard motor 1.
As shown in FIG. 2, there are arranged, around the engine 3, electrical
equipments, not shown, an intake device 18, a fuel supply system or
apparatus 19, etc. The intake device is mainly composed of a silencer 20,
a throttle body 21, a surge tank 22 and intake manifolds 23 extending from
the surge tank 22 to respective cylinders, these elements being arranged
concentrically on one side, left side in this embodiment, of the engine 3.
The electrical equipments are also arranged concentrically on the side
opposite to the intake device 18.
The throttle body 21 composing the intake device 18 is disposed at a left
front portion, for example, of the crank case 8, and the silencer 20 is
disposed on the upstream side of the throttle body 21 and, on the other
hand, the surge tank 22 is disposed on the downstream side thereof. The
intake manifolds 23 are vertically arranged on the side of the cylinder
block 7 so as to communicate the inside of the surge tank 22 with intake
ports formed to the cylinder head 6.
The fuel supply system 19 includes fuel elements or parts such as filters,
pumps, etc. More concretely, the fuel supply system 19 is composed of low
and high pressure filters 24L and 24H, low and high pressure fuel pumps
25L and 25H, a vapor separator 26, a pressure regulator 27, a delivery
pipe 28 and a fuel injector 29, which are operatively connected
respectively by means of low and high pressure fuel hoses 30L and 30H.
FIG. 3 is a block diagram of the fuel supply system 19 according to the
present invention. The outboard motor 1 of this embodiment is equipped
with a fuel tank 31 on the hull 5 side, and as shown in FIG. 3, a fuel
supply hose 32 extending from the fuel tank 31 is connected to the low
pressure fuel filter 24L.
The low pressure fuel pump 25L driven by a camshaft, not shown,
constituting a valve moving mechanism of the engine, is arranged to the
head cover 10, and the low pressure fuel pump 25L (mechanical pump) and
the low pressure fuel filter 24L are connected to each other by means of
the low pressure fuel hose 30L.
The vapor separator 26 is arranged in a space formed between the side
surface of the cylinder block 7 and the intake manifolds 23, and the vapor
separator 26 is secured to an inside portion of the intake manifolds 23 as
a mount base by means of bolts 33, for example. The vapor separator 26
acts to separate a vapor contained in a liquid fuel, such as gasoline
vapor contained in a gasoline and release only the vapor in air, and the
fuel is fed to the vapor separator 26 from the low pressure fuel pump 25L
through the low pressure fuel hose 30L.
The vapor separator 26 is accommodated with the high pressure fuel pump 25H
for feeding, under a predetermined pressure, the fuel from which the vapor
is separated, to the high pressure fuel filter 24H through the high
pressure hose 30H. The high pressure fuel filter 24H is secured to the
delivery pipe 28 through a bracket 34 disposed to a portion, for example,
between a plurality of fuel injectors 29.
The highly pressurized fuel fed to the high pressure fuel filter 24H is
then fed to the delivery pipe 28 integrally mounted to the intake
manifolds 23 through the high pressure hose 30H. The fuel injectors 29 are
mounted to the delivery pipe 28 for the respective cylinders and the fuel
injectors 29 then inject the highly pressurized fuel into the intake ports
of the cylinders.
A fuel flow-in portion 37 is arranged to an upper portion of an inner
surface of the vapor separator 26 and a needle valve 39 is disposed at an
outlet portion of the fuel flow-in portion 37. A float 40 is also disposed
at a portion near this outlet portion of the fuel flow-in portion 37. The
float 40 is supported to be swingable by means of hinge 41, for example,
to which the needle valve 39 is mounted.
The high pressure fuel pump 25H is mounted to an upstream side of a fuel
discharge portion 38 arranged to the upper portion inside the vapor
separator 26. The inside of the vapor separator 26 is formed as a fuel
reservoir in which the high pressure fuel pump 25H is immersed. A chamber
43 is formed at a lower portion of the fuel reservoir by being sectioned
by a partition plate 42. The pressure regulator 27 as inlet means of the
high pressure fuel is arranged in this chamber 43. The partition plate 42
is formed with a communication port 44 for establishing the communication
between the fuel reservoir and the chamber 43.
As shown in FIGS. 2 and 3, a branch pipe 45 is disposed on the way of the
high pressure fuel hose 30 extending from the high pressure fuel filter
24H to the delivery pipe 28, and one downstream end of the branch pipe 45
is connected to the high pressure fuel hose 30H extending to the delivery
pipe 28 and another one end of the branch pipe 45 is connected to a hose
46 extending to the vapor separator 26, the hose 46 being then connected
to the pressure regulator 27 in the vapor separator 26.
The fuel supply system of the structure mentioned above will operates in
the following manner.
The fuel in the fuel tank 31 is sucked up by the low pressure fuel pump
25L, then filtered by the low pressure fuel filter 24L and guided to the
vapor separator 26 through the fuel flow-in portion 37. When the fuel
level in the vapor separator 26 reaches a predetermined level, the float
40 is floated up and the needle valve 39 closes the outlet of the fuel
flow-in portion 37 thereby to restrict the fuel flow-in condition, thus
preventing the fuel from overflowing. On the other hand, when the fuel
level lowers as the fuel has been consumed, the float 40 is also lowered
thereby to release the outlet of the fuel flow-in portion to again supply
the fuel.
In the vapor separator 26, vapor from the fuel stored therein is separated
and bubbles of the vapor are released in the air (atmosphere), and the
fuel with substantially no vapor is supplied to the delivery pipe 28 by
means of the high pressure fuel pump 25H through the fuel discharge outlet
38 and the high pressure fuel filter 24H. Thereafter, the highly
pressurized fuel is injected into the intake ports through the fuel
injectors 29. During this operation, as far as the fuel injection has been
normally carried out, the fuel pressure in the hose 46 extending from the
branch pipe 45 is less than the prescribed pressure, so that the pressure
regulator 27 is not opened.
On the contrary, at a time when the fuel pressure in the delivery pipe 28
is increased more than the prescribed value because of, for example, the
reduced fuel consumption due to low revolution speed of the engine 3, the
fuel pressure in the hose 46 is also increased. Accordingly, the pressure
regulator 27 is opened and the fuel pressure in the delivery pipe 28 is
lowered.
As mentioned above, according to the arrangement of the pressure regulator
27 in the vapor separator 26, the fuel supply system can be made more
unitive and the number of parts or elements to be arranged can be reduced,
thus making the entire structure simple and compact.
The fuel elements or parts constituting the fuel supply system 19 such as
the high pressure filter 24H, the high pressure fuel pump 25H, the vapor
separator 26, the pressure regulator 27, the delivery pipe 28 and the fuel
injectors 29 are mounted integrally to the intake manifold means 23 as
mount base. Therefore, all the elements or parts of the fuel supply system
19 can be integrally dismounted by removing the low pressure fuel hose 30
from the low pressure fuel pump 25L. As a result, the maintenance of the
engine can be effectively performed and the fuel supply system 19 itself
can be made more unitive. Furthermore, re-assembling of such fuel supply
system can be also done more simply.
Still furthermore, the location of the high pressure fuel filter 24H
between the vapor separator 26 and the delivery pipe 28 can prevent
foreign matters or the like from entering into the fuel injectors 29, thus
the system being reliable.
Still furthermore, according to the present invention, since the fuel
discharge port 38 as the high pressure fuel outlet is formed to, for
example, the upper portion of the vapor separator 26 and the pressure
regulator 27 as the high pressure fuel inlet is located to, for example,
the lower portion of the vapor separator 26, the overlapped arrangement of
the fuel hoses 30H can be prevented, thereby making the pipe (piping)
arrangement compact.
It is to be noted that the present invention is not limited to the
described embodiment and many other changes and modifications may be made
without departing from the scopes of the appended claims.
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